Exemplary embodiments of the invention relate generally to a system and method for controlling a warning horn. Other embodiments relate to control and safety systems at a highway-rail grade crossing.
A highway-rail grade crossing is a location where a highway or other road crosses a train track at the same level (as opposed to the road being routed over or underneath the train track). An engineer will generally use a train's horn at a highway-rail grade crossing to warn oncoming traffic of the train's approach. However, such warnings can be annoying to residents living near the crossing, especially at night. Electronic train horns may be locally mounted as warning horns at the crossing. The warning horn is directional and can be mounted on each side of the crossing, facing the direction of the roadway. The warning horn may be activated as part of a Highway-Rail Grade Crossing Warning System, for example, when a train approaching the crossing is around 300 to 1000 meters from the crossing. A strobe light can be operated in concert with the horn to confirm the functionality of the warning horn system, which may flash throughout the time that the horn is sounding. Train engineers are not required to sound a train-mounted horn as they approach crossings equipped with these systems, provided they can see the strobe light flashing at the crossing.
The electronic horn continues to sound a warning as long as the Highway-Rail Grade Crossing Warning System is active, for example, until the train has completely entered the crossing, or until the train has cleared the crossing. The warning horn system is intended to minimize the noise impact to the surrounding area by localizing the warning to the crossing and by focusing the warning in the direction of the roadway. However, the warning horn is sounded as long as the train is on the approach, regardless of whether or not the warning is actually needed. This may also cause unneeded annoyance for residences living in the near vicinity of the crossing. Accordingly, an improved technique for controlling the warning horn by the Highway-Rail Grade Crossing Warning System would be useful.